Solenoid attachment for electric starting apparatus

Abstract

A fastening arrangement for securing the solenoid of an electric engine starter to an aluminum starter housing. The solenoid has a steel casing formed with a plurality of outer circumferentially spaced radially extending cylindrical bores. The portion of the casing that has the bores is located within a tubular portion of the aluminum starter housing. Portions of the material of the housing, that overlie the bores, is flowed into the bores by a tool that is moved in a generally conical path and which is capable of rotating about its own longitudinal axis. The material that is flowed into the bores secures the solenoid to the starter housing.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. A solenoid to starter housing fastening arrangement comprising, a starter housing formed of aluminum material having a tubular portion that has an annular internal wall, a solenoid having a metallic case one end of which is located within said tubular portion with an end surface of said metallic case engaging said annular internal wall, a plurality of circumferentially spaced radially extending cylindrical bores formed in the portion of said case that is located in said tubular portion of said starter housing, and a cylindrical slug of aluminum housing material integral with said housing in each of said bores, each slug of material engaging an internal cylindrical surface defining a respective bore for fastening said solenoid to said starter housing. 
     
     
       2. A solenoid to starter housing fastening arrangement comprising, a starter housing formed of aluminum material having a tubular portion that has first and second internal annular walls, a solenoid having a metallic case one end of which is located within said tubular portion with an end surface of said metallic case engaging said first annular wall, said case having an outer annular surface portion engaging said second annular wall, a plurality of circumferentially spaced radially extending cylindrical bores formed in said outer annular surface portion of said case, and a cylindrical slug of aluminum housing material integral with said housing in each of said bores, each slug of material extending radially inwardly from said second annular wall and engaging an internal cylindrical surface defining a respective bore for fastening said solenoid to said starter housing. 
     
     
       3. The fastening arrangement according to claim 2 where the outer annular surface portion of the solenoid case has a press-fit with the second internal annular wall of the starter housing. 
     
     
       4. A method of securing a solenoid that has a metallic case to an aluminum housing of an electric starter, the steps comprising, forming a bore in an outer wall of said solenoid case, inserting the portion of the solenoid case that has said bore into a tubular portion of said aluminum housing such that a portion of the aluminum housing overlies the bore in said solenoid case, and then moving material of said aluminum housing into said bore of said solenoid case by engaging said aluminum housing with a tool that applies pressure to said aluminum housing, the longitudinal axis of the tool being inclined to the longitudinal axis of said bore and said tool being moved in a generally conical path and being supported for rotation about its own longitudinal axis. 
     
     
       5. A method of securing a solenoid that has a metallic case to an aluminum housing of an electric starter, the steps comprising forming a radially extending cylindrical bore in an outer wall of said solenoid case, inserting the portion of the solenoid case that has said bore into a tubular portion of said aluminum housing such that a portion of the aluminum housing overlies the bore in said solenoid case, and then moving material of said aluminum housing into said cylindrical bore of said solenoid case and into engagement with an internal cylindrical wall of said bore by engaging said aluminum housing with a tool that applies pressure to said aluminum housing, the longitudinal axis of said tool being inclined to the longitudinal axis of said bore and said tool being moved in a generally conical path and being supported for rotation about its own longitudinal axis. 
     
     
       6. A method of securing a solenoid that has a metallic case to an aluminum housing of an electric starter, the steps comprising, forming a radially extending cylindrical bore in an outer wall of said solenoid case, inserting the portion of the solenoid case that has the bore into a tubular portion of said aluminum housing such that a portion of the aluminum housing overlies the bore in said solenoid case, the outer wall of said case having a press-fit with an internal surface of said tubular portion and having an end surface that engages a surface of said tubular portion when said solenoid case is fully inserted into said tubular portion, and then moving material of said aluminum housing into said cylindrical bore of said solenoid case and into engagement with an internal cylindrical wall of said bore by engaging said aluminum housing with a tool that applies pressure to said aluminum housing, the longitudinal axis of said tool being inclined to the longitudinal axis of said bore and said tool being moved in a generally conical path and being supported for rotation about its own longitudinal axis.